Director dealings: Top men take shine to Stellar Diamonds shares

A sampling exercise at the Buoro site had revealed a high grade of diamonds which have now been sent for valuation and sale.

The company secured a 6.2 million refinancing in March to progress its exploration work at Buoro and at its other mines in the region, and analysts viewed the latest news as a positive development.

Last week chief executive Karl Smithson bought 130,000 shares at 7.49p and now holds 1.53 million shares. Steven Poulton, a non-executive director, bought 135,000 shares at the same price and now holds 669,576 shares.

• Colin Brumpton, a director of AIM-quoted Strontium, has increased his stake with two purchases totalling more than 98,000 shares at around 3p each.

He now holds 2.4 million shares in the consultancy which specialises in identifying and developing of high-growth-potential SMEs.

• Roberto Danino, non-executive deputy chairman at precious metal miner Hochschild, has sold almost 2m of shares. A company he is connected with disposed of 300,000 shares at 625p each.

• Robert Rayne, chairman of the London restaurant chain operator Richoux, upped his stake following strong annual results.

Rayne bought around 1.1 million shares at 15.3p each to increase his family's stake to more than 7.9 million shares.

The company recently reported a move into the black with a 505,000 pre-tax profit made following a year which saw the firm open seven restaurants.

The company, which now operates 13 restaurants under the Richoux, Zippers and Dean's Diner names, also saw a 16 per cent rise in turnover.

• Glenn Collinson, a non-executive director at Edinburgh-based technology group Wolfson Microelectronics, has bought his first stake in the company.

Collinson, a co-founder of Bluetooth specialist CSR, bought 40,000 shares at 215p a time.

• Stephen Dattels, co-chairman at mining group Polo Resources, has bought more than 6.3 million shares at 5.82p a share. The purchase takes his stake up to 220 million shares. Earlier in the week non-executive director Ian Stalker had bought 1.77 million shares at 5.56p a time to take his stake above five million shares.

• Stephen Ackerman, a non-executive at investment trust Gresham House, bought 5,000 shares at 329p each.

• Keith Heller, a non-executive director at UK Coal, has upped his stake with the purchase of just over 200,000 shares at around 40p each. He now holds 354,872 shares. His purchase came after shares in the company fell sharply after it announced losses of more than 100m for the second year running. The company's recently appointed chairman Jonson Cox has said the group had now embarked on a "complete overhaul of strategy".